1. Field of the Invention
The present invention relates to a biological optical measurement apparatus which measures optical characteristics of body tissue, a measurement probe connected to the biological optical measurement apparatus, and a biological optical measurement system.
2. Description of the Related Art
In recent years, a biological optical measurement apparatus is known which irradiates illumination light to body tissue and estimates the nature of the body tissue on the basis of measurement values of detected light reflected or scattered from the body tissue. The biological optical measurement apparatus is used in combination with an endoscope for observing an internal organ such as a digestive organ. As such a biological optical measurement apparatus, a biological optical measurement apparatus is proposed which uses LEBS (Low-Coherence Enhanced Backscattering Spectroscopy) that detects the nature of body tissue by irradiating low-coherence white light whose spatial coherence length is short from the tip of an illumination fiber of a measurement probe to the body tissue and measuring intensity distribution of scattering light of a plurality of angles by using a plurality of light receiving fibers (see US Patent Application Laid-open No. 2010/0053632).
The biological optical measurement apparatus and the measurement probe described above are optically connected to each other by using an SMA (Sub-Miniature Type A) connector. FIG. 13 is a cross-sectional view illustrating a state in which SMA connectors are used as connectors to connect a conventional biological optical measurement apparatus and a measurement probe. In a biological optical measurement apparatus 1000 illustrated in FIG. 13, a connector unit 1002 is fixed to a housing 1001 by a nut 1003. An SMA connector 1005 holding an optical fiber 1004 and an SMA connector 1006 holding an optical fiber 1004 are inserted into the connector unit 1002 from both ends of the connector unit 1002, respectively, and screwed and fixed to the connector unit 1002. Thereby, an end surface of the SMA connector 1005 and an end surface of the SMA connector 1006 come into contact with each other, so that both optical fibers 1004 are optically connected to each other.